Two trains A and B of length 400 m each are moving on two parallel tracks with a uniform speed of `72 km h^(-1)` in the same direction, with A ahead of B. The driver of B decides to overtake A and accelerates by `1 ms^(-2)`. If after 50s, the guard of B just brushed past the driver of A, what was the original distance between them ?

Explanation

To solve the problem, we need to determine the original distance between the two trains A and B when the guard of train B brushes past the driver of train A after 50 seconds. Here’s a step-by-step breakdown of the solution:

### Step 1: Convert the speed of the trains from km/h to m/s
The speed of both trains is given as `72 km/h`. To convert this to meters per second, we use the conversion factor:

\[ \text{Speed in m/s} = \text{Speed in km/h} \times \frac{5}{18} \]
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